Shield



FIG. 1 is a top isometric view of our design for a shield;

FIG. 2 is a front view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a left side view thereof, the right side view being a mirror image of the left side view;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a bottom isometric view thereof.

The broken lines depict portions of the shield that form no part of the claimed design. 

CLAIM We claim the ornamental design for a shield, as shown and described. 